David William Smith

Techniques for multigigabit coherent optical transmission

It has been anticipated that the main roles for coherent optical techniques will be to provide increased capacity both for long-haul transmission and wide-band signal distribution. This could be achieved by the combination of high-data-rate transmission and fine-grain WDM. To this end, heterodyne detection experiments have recently been extended into the gigabit regime but difficulties not present at lower data rates have been encountered. This paper discusses a range of technical solutions to these problems, including broad-band receivers, homodyne detection, and phase diversity reception, and reviews their current status.

Laser Transmitter Design for Optical Fiber Systems

The need for high performance sources for optical fiber telecommunications systems has resulted in the development of laser transmitters that incorporate high efficiency coupling optics, sophisticated control electronics, and high-speed modulation circuits. Present thinking on system development indicates the need for transmitters to have, in addition, much improved spectral characteristics. This paper reviews the present status of laser transmitters and describes likely future trends.

Multidimensional optical switching networks

A novel switch fabric which trades the inherent spectral and spatial bandwidth of optical systems against a reduction in equipment complexity is described. The architecture, which is based on a multiple access bus structure, is nonblocking in the wide sense and capable of graceful growth. It also offers the possibility of achieving the theoretical minimum of crosspoints needed for a generalized interconnection network. It is anticipated that experimental multidimensional bus switched (MDBS) networks with Tbit throughput could be designed around currently available research components. The design of such networks and the technology options are described. It is noted that there a number of technology paths open that would lead to very large MBDS networks with throughputs well beyond what is readily obtainable with conventional electronic architectures; one interesting development in this direction is the D fiber back plane.<<ETX>>

Multidimensional optical interconnection networks

A family of fixed and reconfigurable optical interconnection networks offering the potential of Terabit throughput are described. The designs are based on a bus architecture that combines space, wavelength and other multiplexing methods and have the following attractive features:- graceful growth; wide-sense non-blocking operation; low space switch crosspoint count; and simple control algorithm.

High-speed optical interconnects for parallel processing and neural networks

Two dimensional arrays of InGaAsIJnP based multiple quantum well surface modulators driven by standard high-speed CMOS have been demonstrated in experimental parallel optical interconnect and artificial neural processing systems. Transition times were fast enough for lOOMBit/s operation and the potential exists to increase array dimensions to include 100s of devices and transmission rates to many GBit/s. Novel architectures employing computer generated holographic beam splitters and weight matrices outside the modulator and detector layers were employed.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.